This invention refers to a system comprising a number of transmitting microcells sequentially disposed and integrated along the road.
More specifically, this invention refers to a system for carrying out communication between xe2x80x9cnxe2x80x9d transmission sites which are conveniently distributed along the road to provide the drivers with useful information concerning the traffic conditions and/or others.
At present, there are no specialized road radio services in the market for helping drivers by supplying them with useful information on the route they shall follow.
Such a service shall therefore serve as a communication means among road operators, patrolmen, mechanical and personal help services operators, and the like, frequently required in all municipal, state and federal roads.
Thus, the object of this invention is to provide then a road radio type communication system for supplying the users of said road with useful information through the radios of their own vehicles.
According to the present invention, a system for distributing signals in confined areas, such as a road, is provided, which system comprises the transmission of sound through transmitting microcells sequential and conveniently integrated and disposed along the road, including access areas and neighbor areas. This coverage is restricted to distances of up to 300 or 500 meters transversal to the road axis, so that the service is limited only to the assistance of users in a specific way. The cells have a pattern linear coverage of up to approximately 2.5 km which can be extended up to approximately 20 km on basis of the planar topography of the road and by potency adjustment of the transmitter of each cell.
The transmitting microcells according to this invention allow for the reception of frequency modulated signals in common receiving radios of the vehicles that drive along the road. Such a reception shall be monotonally performed (music and voice) by 36KOF3EJN modulation process which can be changed by the addition of coded signals to be also transmitted for eliminating at consistent levels the interference effects and interaction among adjacent microcells and/or those alternately disposed on the road.
The transmitting microcells according to this invention shall operate in the 87.9 MHz frequency range which can even be defined for this type of service all over the country. It can also operate at FM frequency range which can be attributed to the type of service.
Every transmitting microcell is actuated by a xe2x80x9cFixe2x80x9d frequency for repeating and distributing the information signal, which frequency cannot be directly tuned by the common receiving radios of the vehicles, and takes the information to be directly retransmitted and/or repeated by transmitting microcells to the users along the road. The number of xe2x80x9cFixe2x80x9d frequencies to be used depends on the area topography where the road is constructed and the different signal levels able to actuate the transmitting microcells.
The geographical location of the stations transmitting different xe2x80x9cFixe2x80x9d frequencies is defined for every road as a function of the coverage of xe2x80x9cnxe2x80x9d transmitting microcells disposed along thereof. These same repeating stations shall be directly linked among one another and/or by satellite, thus allowing for a full integration of the information for specific portions or for the extension of the road with the likelihood of an integration all over the country as well.